Remote config

KMPShip integrates Firebase Remote Config to allow you to dynamically change the behavior and appearance of your app without requiring users to download an update.

With Remote Config, you can:

• Enable or disable features remotely
• Customize app behavior for different audiences
• Roll out features gradually
• Experiment with A/B testing

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Using Remote Config in KMPShip

KMPShip provides a structured and type-safe way to work with Remote Config values by categorizing them into Feature Flags and App Configuration Parameters.

Create your keys in Firebase Remote Config

Open your project in Firebase console and navigate to the Remote Config section:

https://console.firebase.google.com/u/0/project/{yourProjectId}/config/env/firebase

Replace {yourProjectId} with your actual Firebase project ID.

Here, you can define your keys and their default values.

Declare your keys in KMPShip

All keys defined in your Firebase Remote Config console must be added to the RemoteConfigKey enum class:

enum class RemoteConfigKey(val value: String) {
    EXAMPLE_BOOLEAN_KEY("my_boolean_key"),
    EXAMPLE_STRING_KEY("my_string_key"),
}

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Feature Flags (Boolean values)

Boolean Remote Config values are considered Feature Flags in KMPShip.

Steps to add a Feature Flag:

1. Add a new value to the FeatureFlag enum class Location: com.example.myapp.domain.entity
2. Add a mapping in the RemoteConfigFeatureFlagModelMapper class Location: com.example.myapp.data.source.firebase.remoteconfig.mapper
3. Use GetFeatureFlagUseCase from your ViewModel Location: com.example.myapp.domain.usecase.settings

Example:

1. Define in Firebase Remote Config:

   "onboarding_enabled": true
   

2. Update RemoteConfigKey enum class:

   enum class RemoteConfigKey(val value: String) {
       ONBOARDING_ENABLED("onboarding_enabled"),
   }
   

3. Update FeatureFlag enum class:

   enum class FeatureFlag(val defaultValue: Boolean) {
       ONBOARDING_ENABLED(true),
   }
   

4. Update RemoteConfigFeatureFlagModelMapper mapper:

   class RemoteConfigFeatureFlagModelMapper : EntityToModelMapper<FeatureFlag, RemoteConfigModel> {
   
       override fun convertToModel(entity: FeatureFlag): RemoteConfigModel {
           val key = when (entity) {
               FeatureFlag.ONBOARDING_ENABLED -> RemoteConfigKey.ONBOARDING_ENABLED
           }
   
           return RemoteConfigModel(key = key)
       }
   }
   

5. Use in ViewModel:

   val isOnboardingEnabled = getFeatureFlagUseCase.execute(
       getFeatureFlagUseCase.InputParams(
           featureFlag = FeatureFlag.ONBOARDING_ENABLED
       )
   )
   

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App Configuration Parameters (Strings, Numbers, Arrays...)

All other Remote Config value types are considered general App Configuration Parameters.

Steps to add an App Configuration key:

1. Add a value to the AppConfiguration data class Location: com.example.myapp.domain.entity
2. Add mapping in AppConfigurationRepositoryImpl Location: com.example.myapp.data.repository
3. Use AppConfigurationRepository to access the value Location: com.example.myapp.domain.usecase.config (e.g. GetAppRatingAskPeriodMonthsUseCase)

Example:

1. Define in Firebase Remote Config:

   "app_rating_ask_period_months": "3" // Period between two requests to show in-app review/ratings (in months)
   

2. Update RemoteConfigKey enum class:

   enum class RemoteConfigKey(val value: String) {
       APP_RATING_ASK_PERIOD_MONTHS("app_rating_ask_period_months"),
   }
   

3. Update AppConfiguration data class:

   data class AppConfiguration(
       val appRatingAskPeriodMonths: Int,
   )
   

4. Update AppConfigurationRepositoryImpl repository implementation:

   class AppConfigurationRepositoryImpl(
       private val localAppConfigurationDataSource: LocalAppConfigurationDataSource,
       private val remoteConfigDataSource: FirebaseRemoteConfigDataSource,
   ) : AppConfigurationRepository {
   
       override suspend fun getAppConfiguration(): AppConfigurationRepository.OutputParams.GetAppConfiguration {
           if (localAppConfigurationDataSource.appConfiguration == null) {
               val appRatingAskPeriodMonths = remoteConfigDataSource.getLong(key = RemoteConfigModel(key = RemoteConfigKey.APP_RATING_ASK_PERIOD_MONTHS).key.value, defaultValue = 3)
   
               localAppConfigurationDataSource.appConfiguration = AppConfiguration(
                   appRatingAskPeriodMonths = appRatingAskPeriodMonths.toInt(),
               )
           }
   
           return AppConfigurationRepository.OutputParams.GetAppConfiguration(appConfiguration = localAppConfigurationDataSource.appConfiguration!!)
       }
   }
   

5. Use in code:

   val months = appConfigurationRepository.getAppConfiguration().appConfiguration.appRatingAskPeriodMonths
   

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Remote Config setup complete

You have successfully set up Remote Config in your KMPShip project. You can now manage feature flags and app configuration parameters dynamically through Firebase.